National Clay pipe Institute [NCPI]
National Clay Pipe Institute is a not for profit trade association comprised of manufacturers of vitrified clay pipe.
http://www.ncpi.org/

Rinker Materials Corporation.
Rinker Group
http://www.rinkermaterials.com/ProdsServices/ConcretePipe/default.shtml

Plastics Pipe Institute - PPI
The Plastics Pipe Institute (PPI) is the trade association representing the plastic pipe industry. Site includes technical information about the use of plastic pipe for water, drainage, fuel gas, conduits, plumbing, and heating. Membership rosters available for all pipe divisions.
http://www.plasticpipe.org/

Perma-Pipe, Inc.
Manufactures pre-insulated pipe and double containment pipe for the oil and gas industry. Also offer leak detection and location, heat traced cathodic protection systems and pipe inspection services.
http://www.permapipe.com/

No-Dig-Pipe, Microtunneling Clay Pipe
No-Dig, A Division of MCP Industries Inc is the manufacturer of the first rigid bodied, clay pipe for use in microtunneling, sliplining, pipe bursting and in casings in the United States. Our first installation was in Houston Texas in April 1992. Since that time, over 70,000 linear feet of NO-DIG pipe have been installed.
http://www.no-dig-pipe.com/

Clow Water Systems Pipe and Fittings
Clow Water Systems Company has been one of the United States premiere manufacturers of iron pipe and fittings in the waterworks industry.
http://www.clowwatersystems.com

Ontario Concrete Pipe Association

http://www.ocpa.com/

Illinois Concrete Pipe Association
The Illinois Concrete Pipe Association is a non-profit trade association composed of concrete pipe producers (and affiliated companies) serving Illinois sewer and culvert market
http://www.il-concretepipe.org/

Wisconsin Concrete Pipe Association
Trade association representing concrete pipe manufacturers in Wisconsin. Product information and membership roster.
http://www.wcpa.com/

Liberty and Rocky Mountain Pipe
Liberty Pipe Companies supplies, designs, manufactures, fabricates, and installs equestrian, livestock and estate fencing and buildings. Performance Pipe Products, Fencing, Pipe, and Asset Recovery.
http://www.libertypipe.com/